Introduction
Tides are caused by the gravitational pull of the moon and sun. But the height of the tide depends greatly on local geography: narrow bays, shallow shelves, and funnel-shaped coastlines amplify tidal ranges.
The highest tides in the world occur in bays and estuaries where the shape of the coastline concentrates the tidal energy into an ever-narrowing space.
1. Bay of Fundy, Canada
- Max Tidal Range: 16.3 m (53.5 ft)
- Location: New Brunswick/Nova Scotia
- Volume: 160 billion tonnes of water per tide
The Bay of Fundy has the highest tides in the world. The bay's funnel shape and natural resonance period amplify the tidal range to over 16 meters.
160 billion tonnes of water flow in and out of the bay with each tide cycle, more than the combined flow of all the world's freshwater rivers.
2. Ungava Bay, Canada
- Max Tidal Range: 16.8 m (55 ft, disputed)
- Location: Northern Quebec
- Debate: May exceed Bay of Fundy
Some measurements suggest Ungava Bay has even higher tides than the Bay of Fundy. The remote location makes consistent measurement difficult.
3. Bristol Channel, UK
- Max Tidal Range: 15 m (49 ft)
- Location: England/Wales
- Notable: Severn Bore tidal wave
The Bristol Channel has the highest tides in Europe. The funnel shape of the channel creates the famous Severn Bore, a tidal wave that surfers ride upstream.
4. Mont Saint-Michel, France
- Max Tidal Range: 14.5 m (47.5 ft)
- Speed: Water advances at 1 m/s
- UNESCO: World Heritage Site
Mont Saint-Michel is famous for its dramatic tides that can advance across the flat bay at walking speed. The medieval abbey becomes an island at high tide.
5. Cook Inlet, Alaska, USA
- Max Tidal Range: 12.2 m (40 ft)
- Location: South-central Alaska
- Bore: Turnagain Arm bore tide
Cook Inlet's Turnagain Arm has a famous bore tide that creates a surfable wave. The extreme tidal range creates dangerous mud flats that have trapped and killed people.
6. King Sound, Australia
- Max Tidal Range: 11.8 m (38.7 ft)
- Location: Western Australia
- Notable: Horizontal Falls nearby
King Sound has the highest tides in Australia. The nearby "Horizontal Falls" are created by massive tidal flows forcing water through narrow gorges.
7. Gulf of Khambhat, India
- Max Tidal Range: 12 m (39 ft)
- Location: Gujarat
- River: Narmada estuary
The Gulf of Khambhat has the highest tides in India. The funnel-shaped gulf amplifies the tidal range, creating treacherous conditions for shipping.
8. Penzhinskaya Bay, Russia
- Max Tidal Range: 13.4 m (44 ft)
- Location: Sea of Okhotsk
- Potential: Enormous tidal energy potential
Penzhinskaya Bay has some of the highest tides in the Pacific. Russian engineers have proposed a massive tidal power station that could generate 87 GW.
Key Facts
- The Bay of Fundy's tidal range exceeds 16 meters, enough to submerge a 5-story building.
- 160 billion tonnes of water move with each Bay of Fundy tide.
- Tidal bores (waves that travel up rivers) occur in several high-tide locations.
- The highest tides are always in funnel-shaped bays and channels.
- Ungava Bay may actually have higher tides than the Bay of Fundy, but measurement is difficult.
Fun Facts
- You can walk on the ocean floor at low tide in the Bay of Fundy and be under 16 m of water 6 hours later.
- The Severn Bore in England is surfed by adventurous wave riders.
- Mont Saint-Michel's incoming tide was described as moving "as fast as a galloping horse."
- Cook Inlet's mud flats can trap a person like quicksand.
Final Thoughts
The world's highest tides are dramatic demonstrations of gravitational forces amplified by geography. From the Bay of Fundy's 16-meter swings to the Severn Bore's surfable wave, extreme tides reshape coastlines twice a day.
